Grind the cumin, coriander and cardamom pods using a pestle and mortar until the cardamom pods have opened to release the seeds. Discard the shells.
Heat the oil in a small, sturdy roasting pan and fry the spices for 30 seconds. Add the lamb and onions and toss with the spices. Transfer to a preheated oven, 180°C (350°F), Gas Mark 4, and cook for 40 minutes until the lamb and onions are browned.
Return to the hob and stir in the ginger, garlic, turmeric and rice. Add the stock and bring to the boil. Cover with a lid or foil and cook over the lowest setting for about 30 minutes until the rice is tender and the stock has been absorbed.
Stir in the pine nuts and apricots and season to taste. Scatter with the rocket and fold in very lightly. Pile on to serving plates and serve immediately.